It seems that there's no build for Ubuntu 11.10 (Mint 12) in that PPA, I think that is why you get 404 errors. That kinda sucks...
Try this: remove the PPA you added (since it obviously doesn't work) and add ppa:stebbins/handbrake-releases (just click on "Add..." and paste the name). When it is added (two new lines appear, but ignore the one that says "(Source Code)"), click on it (the "binaries" one), click "Edit", and in the "distribution" field type "natty" instead "oneiric". That will force it to get the packages for Ubuntu 11.04 but it should work. Now, open terminal and type these:
sudo apt-get update
sudo apt-get install handbrake-gtk
That should be it. If it fails for any reason, report here and we'll try to help you further.
Regarding the portable version, "portable" only means that it needs no install, just download and run. If 32bit works for you (it should, but give it a go), it might be the easiest way. As stated, it will not use more that 3.25GB of RAM (but that's hardly an issue since some of your 4GB will always be busy anyway, so it will probably never hit that limit). 64bit would be able to use whatever.
I am under an impression that you haven't downloaded or installed anything, just added a PPA, so no need to remove anything except the PPA. Correct me if I'm wrong.
Last edited by veggen
on Fri Feb 24, 2012 8:23 am, edited 2 times in total.